Oil burner



June 24, 1941. w MlL 2,246,809

' OIL BURNER Filed April 17, 1939 4 Sheets-Sheet l Jan/um H0 WARD W MILLER,

June 24, 1941 H. w. MILLER 2,246,809

OIL BURNER I Filed April 17, 1939 4 Sheets-Sheet 2 Hi i: i-mlil June 24, 1941. Y w MULLER zvmfifiw OIL BURNER Filed April 17, 1959 4 Sheets-Sheet 5 Y/IOWARD W MILLER,

all/WW June24, 1941. H.W. MILLER 2,246,809

" OIL BURNER Filed April 17, 1959 4 Sheets-Sheet 4 Jmwm Nowmw W MILLER,

WWO

Patented June 24, 194.1

2,246,809 I on. BURNER.

Howard W. Miller, Piqua, Ohio, assignor of onefourth to C. F. Rldenour, Piqua, Ohio Application April 17, 1939, Serial No. 268,164

13 Claims.

The present invention relates to liquid fuel furnaces and more particularly to an improved oil burner for the furnace.

Practically all of the prior ant furnaces cost more to heat with oil than with coal and, in general, they operate satisfactorily only when. supplied with oil of the grade for which they are designed. Any slight variation from this grade of oil will usually cause serious trouble. For example; the refineries class as No. 2 fuel oil, the grade ranging from 30 degrees to 35 degrees Baum. This five-point variation quite frequently represents the difference between satisfactory and unsatisfactory performance of the prior art burner. In other words, one sample No. 2 fuel oil may prove quite satisfactory and another sample No. 2 may not give satisfaction at all.

Moreover, practically all of the prior art oil burners employ forced air for draft and also forced feed for the oil which obviously requires motor driven apparatus and necessitates lectricity. Any interruption in electric service entirely disrupts the heating plant, and furthermore, this electric service must be charged to heating costs.

Many of the prior art burners leave a great deal of soot or other unburned carbon in the oil passageways, thus preventing the free flow of fuel and requiring frequent cleaning or replacement of parts. In some of the burners, a hard scale or slag is formed in the bottom of the bowl, and if left for a sufficient length of time will become so thick as to prevent ready heat conduction through the bowl and, therefore, may cause a burn-out.

Practically all of the difficulties experienced in connection with prior art oil burners may be laid to the fact that combustion is incomplete, or if complete, the combustion'is of a progressive character and does not take place entirely within the bowl. Thus, the flue gases may contain a large percentage of carbon monoxide which represents heat loss andleaves the flue or chimney at a considerable velocity.

The objects of the present invention are to provide an improved liquid fuel burner which is simple to manufacture, therefore, inexpensive and is exceedingly efficient in operation; to provide an improved burner which can operate equally well on all sorts of liquid fuel and without special design for each fuel. These fuels include gasoline and the cheaper kind, such as kerosene, first, second or third grade oil, crude oil and crankcase drainings; to provide an improved liquid fuel burner in which the combustion is so complete, regardless of the character of the fuel, that no unburned carbon or scale is left in the passageways of the burner or in the combustion bowl; to provide a liquid fuel burner which depends solely on a natural induced draft and neither requires a forced draft nor a forced oil feed. The draft obtained in my improved furnace. supplies sufficient combustionsupporting gases to assure complete and instantaneous combustion of the fuel in the combustion chamber.

An object corollary to the last-mentioned object is to provide an improved liquid fuel burner in. which the combustion is so complete that the escaping flue gases have a low velocity, and a complete reduction of these gases to carbon dioxide takes place within the combustion chamber.

nace in which the burner and draft pipe are readily accessible for inspection. This particular object is attained in brief by mounting the burner and draft pipe as a hinged unit which is adapted to swing outwardly from the furnace.

The final object of the present invention is to provide an improved liquid fuel burner, in which an easy volatilized fluid is employed for starting and then a switch-over to a less volatilized fluid is employed for the regular operating condition.

Other objects and features will be apparent as the specification is perused in connection with the accompanying drawings, in which- Figure 1 is a side elevational view, partly in section, of the improved liquid fuel furnace including the tank accessories.

Figure 2 is a, top plan view of the furnace shown in Figure 1.

Figure 3 is a greatly enlarged fragmentary vertical section of the burner and down draft pipe employed in the improved furnace.

Figure 4 is a sectional view taken along line 4-4 in Figure 3.

Figure 5 is a side elevational view, looking into the hinged air intake unit.

Figure 6 is an elevational view of the entire furnace without the fuel tank accessories and the clown draft pipe. A heat shield for the down draft pipe is shown insection. This view does notrepresent the final position of the illustrated parts.

Figure 9 is a view, partly in section, and taken through. a modified form of burner which includes air cooling instead of water cooling.

Figure is an enlarged sectional view, taken along line lO-IO in Figure 6 of the water-cooled burner. This view showsa typical method of starting when using a highly volatilized liquid passing through the inner feed pipe. The fact that this liquid is readily volatilized is inidcated by the light arrow lines.

Figure 11 is a view showing the burner of Fisure 10 in a running condition and using a low grade of fuel passing through the outer feed pipe. The fact that this fuel is of low grade is indicated by the heavy arrow lines.

Figure 12 is a sectional view similar to Figure 10, but showing the burner in a starting condi-' tion when using a low grade fuel oil passing through the outer pipe.

Referring to. the drawings, numeral l designates a combustion bowl of my improved furnace.

This bowl is preferably made of cast iron and takes the form of a taperedcylindenand ia.pro-. vided at the bottom, 1. e., the portion of smallest diameter, with a heavy base I. The inner surface of the base tapers downwardly toward the center, as seen more clearly in Figure 3, for reasons which will explained hereinafter.

The-bowl 1 is pre erably flanged at the top, as indicated at 3, and a radiator or heat drum 4 is secured to the flange. The drum is closed at the-top by acover 5 and terminates in an upright flue pipe 6. An opening may be provided in the cover 5 and a removablelid I employedtocoverthe opening. I

As seen more clearly in Figures 1 and 5,'the drum 4 is provided at the front ofthe furnace with a large rectangular opening 8 which serves as an air intake for the burner to be described hereinafter. This opening is adapted to receive a relatively large cavernous casting 9 which has a flat bottom, as indicated at H), and perpendicularly mounted sides H, as seen more clearly in Figure 6, bridged by a roof or top member l2 which is inclined downwardly at the rear to meet the base II], as indicated in Figure 1. The casting 9 is hinged to the bowl I, as indicated at l3 (Figures 1 and 5), the casting carrying a flange [4 along its upper and side edges so that the casting may be rotated about the hinge to swing outwardly, i. e., away from the furnace, when desired. Its normal position is that shown in.- Figure 1, in which the flanges l4 abut the surface of the drum 4.

The base iii of the casting 9 has an opening which receives the top end of a down draft pipe or cylinder l5 made of any suitable metal. Surrounding this cylinder and secured to the base In, there is another cylinder l6 of heavy metal and having a conical configuration. The cylinder l6 extends downwardly for practically the entire length of the cylinder l5. The lower or smaller diameter portion of the conical member I6 is provided with a transversely extending deflector or bafile IT, as seen more clearly in Figure 3. This baffle preferably takes an arcuate configuration with the concavity facing the bottom of the bowl.

The bowl is provided with an opening in the bottom to receive the improved burner unit which is shown in detail in Figures 3, 10 to 12. The

The latter is contained in a drum IS, the arrangement being such that the starting fuel tank I8 is secured to the operating fuel tank l9 in any suitable manner, for example, by the encircling strap 20 at the top and the foreshortened strap 2 I at the bottom. A small feed pipe 22 is taken from the bottom of the tank I9 through a hand-operated valve 23 to the bottom of the burner. A larger pipe 24 is connected to the lower end of the drum l9 and passes through a shut-off valve 25 through a length of pipe 26 to a pipe coupling 26 which is screwed into the bottom of the burner. As will be explained hereinafter, the pipes 22 and 26 connect with different portions of the burner. In addition to the oil pipes, there is a water inlet pipe 21 and a water outlet pipe 28 connected to the burner, these pipes being attached to a water tank 29, on which rests the drum 19, as indicated at '30. A water} vel gauge 31 may be provided on the tank 29. p

As shown more particularly drum l9 with the tank l8 may be removed from its pedestal by grasping the handle 32 (after the tanks are disconnected from their pipes) so that the tanks may be filled with fuel in a convenient manner.

The bowl I is supported from a base 33 of cast iron through the adjustable rod supports 34 which ,abut"'lugs"35 cast into the bowl: The watentank 29 is also secured to the base 33 by the bolted flange 36. As shown in Figures 1 and 2, there is provided an upright metal heat shield 31 of arcuate configuration and supported from burner preferably is started on a highly volatilizathe base 33 by the angle irons 38. It will be noted that the heat shield 31 extends practically the entire height of the furnace and its function is to shield the fuel tanks 3 and I9 from direct radiation from the furnace drum 4 and the bowl I.

The burner proper is shown in enlarged detail in Figures 3 and 4. The burner comprises a cylindrical shell 39 which is preferably machined snugly to fit the opening in the base member 2 of the bowl I. The upper portion of the shell is closed by a transversely extending top piece 40 which has an overhanging flange indicated at 41 and is provided with a central opening 42. The flange 4| is seated on an asbestos gasket 43 contained within a-recess in the base 2. The top piece 40 is provided with a spherical surface and has a nut insert 44 which conforms to the spherical configuration of the top piece 40.

There is a pipe 45 passing through the opening 42 and is threaded into the nut insert 44 at one end and continues through an opening in the bottom of the shell 39. The latter preferably takes a conical configuration at this point. The lower end of the pipe 45 is secured to the shell by a nut 46 which presses against a water-tight gasket 41. The pipe 45 is threaded into the coupling 26' (Figure 1) and, as stated hereinbefore, receives the fuel for operating the burner.

There is a pipe 48 arranged within the pipe 45 and concentric therewith, this pipe being provided at the top with a threaded nut 59. As shown more particularly in Figure 8, the nut 50 is provided with four radially extending grooves 5|, preferably of semi-circular configuration and the purpose of which will be pointed out. Resting on the top piece 40, there' is a disk 52 ofarcuate configuration and having a number of openings iris-"gastritis pass.

53 equidistantly spaced around the outer periphery of the disk, as seen more clearly in Figure 8. The disk 52 is provided with a downwardly extending lip 54 which tightly fits a shoulder provided on the top piece 40. The nut 50 serves to hold the lip 54 against the said shoulder by tightening the disk against the central pipe 48.. As seen more clearly in Figure 3-, the central portion of the disk 52 curves downwardly so as to provide a seat for the nut 50, and this curvature is such as to leave a small annular opening between the upper edge of the pipe 45 and the inner surface of the disk.

The rate of fuel flow from the inner pipe 48 into the burner is controlled to some extent by the size of the grooves For an ordinary size burner, I have found that four equidistantly spaced grooves of approximately across and 5;" deep will pass the necessary amount of fuel from the pipe 48.

On the other hand, the rate of fuel fiow from the outer pipe 45 into the burner is controlled in part by the small annular opening between the upper edge of pipe 55 and the lower surface of the disk 52, also by the size of the openings In a practical installation, I have found that this annular opening may have a width of approximately /8 and the openings53 may likewise be approximately A3" diameter.

Concentritzally arranged with respect to the disk 52 and directly above the latter, there is a second disk 55 of substantially the same con iiguration as the disk 52. The disk 55 preferably has its edge serrated as indicated at 55 in Figure 8. The purpose of these serrations will be explained. The disk 55 is carried on a pin 55 which projects for a short distance into the central pipe 55 and is flattened preferably at three points about its periphery so as to give a triangular cross section, as indicated in Figure 7. Three small spaces indicated at 58 (Figure '7) are, therefore, left between the pin 51 and the pipe 55 through which the fluid in pipe 45 may The distance between the disks 52, 55 is not as critical as the size of thegrooves 5| and the openings 55, except at the periphery where the distance between the edges of the disks should be sufficiently small as to cause the fuel to emerge in thin sheet form suitable for rapid combustion.

The disk 55 and the pin 51 are held in place solely by gravity and consequently are readily removable. The disk 55 has secured thereto, as by riveting, a plurality of angle members 59 bolted to the down draft pipe l5, as seen more clearly in Figure 3. The top end of this pipe is tightly received in the opening in the base In of the air intake casting 5 and thus the pipe i5 is readily removable in the same manner as the disk 55.

Figure 6 shows the manner in which the air intake casting 5,together with ally of the parts secured thereto, including the down-draft pipe 55, support shield l5 and the upper disk 55 may be swung about the hinge 13. It is apparent that, in this position, the lower surface of the disk 55 of the burner is exposed to View and a ready inspection can also be made of the upper surface of the lower disk 52 including all of the fuel passageways.

The shell 39, therefore, supports an outer pipe 45, an inner pipe 48, the pair of disks 52, 55 and also the down draft pipe 15'. The shell is, in turn, rigidly secured to the bottom surface of the bowl I by a central yoke 60 which is secured to the shell by the set screws 6|, the yoke being passing through the inlet pipe 21 preferably fills the entire space between the outer fuel pipe and the shell 39 with a cooling fluid, the purpose of which will be described presently. The circulation of the Water is effected by thermosiphon action and the level of the water is determined by thegauge 3! (Fig. 1).

The various methods of starting the burner are shown in Figures 10 and 12 and the running condition is shown in Figure 11. I prefer to start my improved burner by using an easy atomized fuel, for example, gasoline or kerosene contained in the tank 55. Assume that the valve 25 (Fig. 1) has been opened, but the valve 25 is closed, kerosene will flow through the pipe 22, up through the central pipe 55, past the flattened surfaces of the pin 55, out through the grooves and into the space between the disks 52 and 55. This oil is fed rather slowly by gravity and will travel along the upper surface of the disk 52, completely wetting the upper surface of the disk. As the oil oozes out from the edge of the disks, it is collected in a nannular groove cast in the base 2. After this groove is filled with the oil, the latter is ignited in any suitable manner, for example, by means of a gasoline torch 55 of standard design, the nozzle of which may be introduced into the bowl through a large opening which is provided with a hinged cover 55. The heating of the kerosene in the groove 55 causes more kerosene to be drawn through the inner pipe until the base 2 becomes quite hot. In case more kerosene is introduced at the burner than can be collected by the groove, the surplus will remain in the position of the groove due to thetaper provided on the base 2. 4

For economical reasons, it is then desirable to switch the operation over to the heavier and cheaper oil consumption. This is done by closing off the valve 25 and opening the valve 25 which causes the fuel oil to pass from the drum l5, through the pipes 25, 25, up through the outer pipe 55 and through the small space between the upper edge of the pipe 55 and the lower surface of the disk 52. This oil thereupon passes over the surface of the nut 54 and the top piece 55. As soon as enough of this oil has been collected at the lip 54, the oil starts to move up-- wardly through the openings 53 and to spread itself evenly around the upper surface of the disk 52. This oil simply drifts or oozes from the peripheral space between the outer edges of the disks 52, 55 where it meets a quantity of air drawn in through the down draft pipe i5.

' It will be noted that this air sweeps laterally across the upper surface of the disk 55 and upon meeting the oil presented thereto at the edge of the disk 55, a highly combustible gas is formed which is completely burned due to the fact that the base 2 had been previously heated by the kerosene. It has been found that the serrations 58 on the disk 55 greatly facilitate this combustion effect, although it will be understood that satisfactory results may still be obtained in the absence of these serrations.

The difference between the starting and operating conditions, particularly in regard to the shape of the flame, may be readily seen by comparing Figures 10 and 11. It will be noted that during the starting period a flame a is formed at the groove 63 and this flame extends radially across the base 2 due to the down draft coming through the pipe l5. The baflle l1 prevents this flame from goin too high in the vertical direction in that it causes the down draft of air to move in a transverse direction and, therefore, forcing the flame over the entire surface of the base 2. This baflle serves exactly the same function when the burner is being operated with a heavy low grade and cheaper oil in causing the heat to be developed for the most part in the heavy section portion of the bowl, as indicated by the lines I).

The flame obtained regardless of the volatility of the oil is white and not blue, indicating that complete combustion has taken place and that the gaseous product of combustion constitutes carbon dioxide and not carbon monoxide, as in the case of the prior art furnaces. The combustion is so complete that, even in the case of crude oils which contain considerable amounts of tar, there is little or no deposit left in the bottom of the bowl. The combustion is practically instantaneous and no cracking of the oil takes place. The velocity of the fuel leaving the edge of the disks is fairly low and does not constitute a spray and the entire combustion of the oil takes place at the lower end of the bowl. Consequently, there is no progressive combustion and the gaseous products have a relatively low velocity, as they pass upwardly through the bowl i into the drum 4 and out through the flue pipe.

Thus, the baiile 81 serves to direct the air descending through the pipe l5 in-such a direction as to restrict the flame to the bottom of the bowl. Moreover, the direction of the down draft is such as to maintain the edges of the disks 52, 55 fairly cool, particularly the serrations on the upper disk 55. By causing all of the combustion to take place at the lower part of the bowl instead of spreading progressively through the upper part of the bowl, I have found that there is little or no tendency for scale to form, even in the case where a very low grade of fuel such as crankcase drainings is used.

Another method of starting my improved burner is shown in Figure 12, in which the crude heavy oil is used for starting fuel by opening the valve 25 and permitting the oil to flow up through the outer pipe 45 into the space between the disk 52 and the top piece 45 and then upwardly through the openings 53, where it oozes out from the edge of the disk, as explained above. When enough of this oil has dripped into the groove 63, a torch 64 is applied to burn the oil.

In accordance with an important aspect of my invention, I have discovered that considerably better results are obtained by way of complete combustion and thereby deriving greatest amount of heat from the fuel by maintaining the burner relatively cool. The coldness of the burner not only increases the down draft of air produced through the pipe l5, but limits the region of combustion to such a position that no burning whatever takes place within the small passageways in the burner and consequently no soot or other unburned carbon is formed in these pasand through the passageways formed between the disk 52 and the insert 54, and between the disks 52 and 55. If the disks 52, 55 or any portion of the top piece 40 were permitted to approach the ignition temperature, there would be a tendency for the flame which normally takes place at the edge of the disks to drift inwardly toward the top of the fuel pipes and, since not enough air would be available at these places. the combustion would be incomplete and soot or other unburned carbon would be formed. However, by maintaining these surfaces cool, the fuel is not only kept in a liquid state until it reaches the region of combustion, and since there is no clogging, the liquid will flow freely and uniformly over the entire surface of the burner, thus giving a uniform or symmetrical flame at the edge of the disks. It is possible that this soot may be formed by causes other than or in addition to premature ignition, but the fact remains that when the disks 52, 55 are maintained at a relatively cool temperature the space between the disks is kept clean, entirely free of soot, and in the absence of the cooling effects this space becomes dirty and coated with a layer of unburned carbon.

It has also been found that, by maintaining the disks 52 and 55 and the passageway therebetween at a relatively cool temperature, i. e., substantially below the preignition temperature of the fuel, the down draft through the pipe 15 is considerably enhanced since the cooler the air, the greater tendency it has to descend. The air in the pipe i5 is maintained at a cool temperature also by the effect of the shield l6 which prevents the hot gases traveling up through the bowl i from striking the pipe 85.

It is not necessary that the liquid 5'? shall remain cool, indeed, it may be desirable to permit this liquid to become heated but not heated to the extent that steam is formed. As long as the liquid maintains the disks 52 and 55 below the ignition temperature of the oil, the water will have served its purpose of enhancing the down draft of air as well as assuring that the fuel passing between the disks remains in liquid form until it reaches the edge of the disks. Inasmuch as the liquid 6'? may run at a fairly high temperature during operation, it will serve the useful purpose of heating up the oil or other fuel passing through the pipes 45 and 138 and thereby facilitate the atomization of the fuel when it reaches the edge of the disks. Obviously, the liquid can be supplied to the shell 39 by thermosiphon effect. As shown in Figure 1, the liquid -67 is obtained from a tank 29 and passes into the water jacket through the pipe 27 and out of the jacket through the pipe 28.

It has been found that by the use of the water 67, explosions within the oil passageways of the burner are eliminated and the entire flame is localized at the edge of the disks where it will effectively heat the thickened portion of the bowl.

Instead of using water for maintaining the temperature of the disks 52 and 55 below preand ignited at the periphery of the disks.

. are less volatilizable.

ignition temperature, I may employ air-cooling. Thus, in Figure 9 I show a heavy cylinder 68 secured to the outer pipe 45 by means of a headless set screw 69. This cylinder abuts the burner and is spaced away from the base 2 of the-bowl as indicated at so as to provide heat insulation at this point. The yoke ring 60 may be secured to the cylinder 68 by means of the set screw 6|, similar to the arrangement shown in Figure 3. The ring 60 may be provided with a plurality of set screws 62 which are forced against the lower surface of the base 2 and thus serve to clamp the burner tightly to the base. As in the case of the water cooling described in connection with Figure 3, the cylinder 68 of heavy metal serves to conduct the heat away from the disks 52 and 55 at such a rate as to maintain these disks at a temperature below the ignition temperature of the oil. The water cooling is, of course, more desirable in this connection inasmuch as the temperature of the water can be more readily controlled.

It is apparent from the foregoing that I have described a furnace in which more nearly complete combustion takes place than in the prior art devices of this character. This improvement has been brought about in part by the enhancement of the down draft, as well as by the more uniform speed of oil through the burner There is no clogging of the passageways, nor a deposition of soot or other unburned carbon which would tend to prevent the free flow of the liquid fuel through the small passageways. It should also be noted that the air which supports combustion is obtained as a natural draft through the air intake casting and requires no blowers and therefore no electrical service whatever. The burner automatically draws in as much air as is necessary in order to complete the combustion. Thus the air control is entirely automatic and as an additional rate of fuel supply occurs as by further opening the valve 25, an increased air supply is automatically provided. The burner performs equally well at low and high rates over a. very wide range. The combustion is so complete that the burner can not only successfully burn the readily volatilized fuels, such as gasoline and kerosene, but also all grades of fuel oil, crude oil and crank-case drainings, which In the case of the crankcase drainings, which usually contain a certain amount of metal, such as babbitt or lead, I have found that this metal is deposited in the bottom of the bowl, not as a hard slag, as in the prior art furnaces, but instead as a powdery mass. This mass may be readily removed from the furnace by simply swinging the air intak'e casting 9 about its pivot l3 and collecting the ash Consequently, the base portion of the bowl remains in a clean condition, which presents the metal of the bowl to the flame for heating and prevents localized hot spots which might tend to burn out the metal. I Moreover, it is not necessary to change the designof the furnace to accommodate the diiferent fuels. The burner operates equally well on all of the fuels due to the enhanced combustion.

It will be understood that I desire to comprehend within my invention such modifications as come within the scope of the claims and the invention,

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a liquid fuel burner, a combustion unit comprising a plurality of concentrically mounted pipes carrying liquid fuel of different grades, a plate secured to the outer pipe and extending transversely thereof, a pair of disks secured to the inner pipe and extending transversely thereof, said plate and disks being spaced from one another, the space between the disks being in communication with the inner pipe and the space between the plate and the adjacent disk being in communication with the outer pipe, said adjacent disk having openings which permit liquid fuel to pass from the space between the plate and the adjacent disk to the space between the disks whereby each of said fuel pipes are in communication with the inter-disk space.

2. In a liquid fuel burner, a combustion unit comprising a plurality of concentrically mounted pipescarrying liquid fuel of different grades, 2. plate secured to the outer pipe and extending transversely thereof, a pair of disks secured to the innerpipeand extending transversely thereof, said plate and disks being spaced from one another, the space between the disks being in communication with the inner pipe and the space between the plate and the adjacent disk being in communication with the outer pipe, said adjacent disk having openings'which permit liquid fuel to pass from the space between the plate and the adjacent disk to the space between the disks whereby each of said fuel pipes are in communication with the inter-disk space, the passageway between each of the outer and inner pipes and the inter-disk space being suficiently small as to cause the fuel to leave the edges of the disks in thin sheet form suitable for combustion.

3. In a liquid fuel burner, a combustion unit comprising a pipe carrying liquid fuel, a plurality of disks mounted in spaced relation over said pipe and extending transversely thereof, the lower one of said disks being secured to the pipe by a nut and the upper one of said disks-being provided with a pin which extends into the pipe, said nut having a plurality of grooves across its face and said pin being of smaller size than the interior diameter of the pipe, the inter-disk space being in communication with the interior of said pipe through said grooves and through the space between said pin and the pipe.

4. In a liquid fuel burner, a combustion unit comprising a pair of concentrically mounted pipes carrying liquid fuel of different grades, a

plate secured to the outer pipe and extending transversely thereof, a pair of disks mounted immediately above said plate, one of said disks being secured to the inner pipe by a nut and the other of said disks being provided with a pin which extends into the inner pipe, said nut having a plurality of grooves across its face, said plate and disks being spaced from one another, the inter-disk space being in communication with the inner pipe through said grooves for fuel passing through the inner pipe, said inter-disk space being also in communication with the outer pipe through said openings and through the space between the plate and' its immediately adjacent disk for fuel passing through the outer pipe.

5. In combination, a combustion chamber, a liquid fuel burner therein and a draft pipe mounted over the burner, said burner comprising a fuel pipe, a plurality of disks extending transversely of said pipe and spaced from one another to form a passageway, said passageway communieating with said pipe and being of sufficiently between the plate and the adjacent disk being in small dimension to cause the fuel to leave the communication with the outer pipe, said adjacent edge of the disks in sheet form suitable for comdisk having openings which permit liquid fuel to bustion, and means for shielding said draft pipe pass from the space between the plate and the from the heat of combustion, whereby the down adjacent disk to the space between the disks draft through said draft pipe is enhanced, said whereby e of said fuel p pes is in communishielding means including a cylinder interposed cation with the inter-disk space, and means for between said pipe and the combustion chamber. prev nt the a u u ati n of unburned carb n 6. In combination, a combustion chamber, a in said pipes. between said plate and the adialiquid fuel burner therein and a draft pipe 10 cent disk, and within the openings of the adJamounted over the vburner, said burner compriscent k, Said ns comprising a Water Jacket ing a fuel pipe, a plurality of disks extending which surrounds the pipes andisinheat-absorbtransversely of said pipe and spaced from one ing relation with respect to said p p d disks another to form a passageway, said passageway nd S P communicating with said pipe and being of suf- 10- n a iquid el u e a combustion u i flciently small dimension to cause the fuel to comprisi a plurality f concentrically mounted leave the edge of the disks in sheet form suitable P p carrying liquid fuel of different gr d for combustion, means for shielding said draft plate secured to the outer pipe and extending pipe from the heat of combustion wherebrthe r nsv r ly thereof. a pair of disks secured to down draft through said draft pipe is enhanced, so e i n pipe a d e e g transversely theresaid shielding means including a oylinder lnterof, d plate and disks being paced from one posed between said pipe and the combustion another, the space between the disks being in chamber, and means for directing the flame communication with the inner pipe and the space emitted from the peripheral space between said w en h plate and the adjacent disk be in disks toward the bottomnof the combustion communication with the outer pipe, said adjacent h b disk having openings which permit liquid fuel to 7. In combination, a combustion chamber, a P s from the pace between the Plate and the liquid fuel burner therein and a draft pipe j n k o e Sp e between the disks mounted over the burner, said burner comprising where y h of s id fu l Pipes is in communia fuel pipe, a plurality of disks extending transcation with the inter-disk pa d a liquid versely of said pipe and spaced from one anoth r cooling medium in, contact with said metal plate. to form a passageway, said passageway communi- 11- A liquid fuel burner comp a l P p eating with said pipe and being of sufllclently a plurality of Spaced arcuate disks extending mall dim n i n t au th 1 t leave t transversely of said pipe, the lowermost disk havedge of the disks in sheet form suitable for comss inkardownwardly ex en g P ripheral flange, bustion, means for shielding said draft pipe from Said burner v n a pl e n hi h he flange the heat of combustion whereby the down draft rests to form a d tight jo a d p s through said draft pipe is enhanced, said shieldin the lowermost disk which permit inter-coming means including a cylinder interposed bemunication between the space formed at the untween said pipe and the combustion chamber, derside of the lowermost disk and the inter-disk' and means for directing the flame emitted from Space, Said fuel P pe communicating W h the peripheral space between said disks toward space between the lowermost disk and said plate. the bottom of the combustion chamber, said last- A q d el b r Comprising a fuel P p mentioned means including a name plate secured a pl lity of sp d ar e di ks extendin to the end of said cylinder nearer the burner and ve y of Said p p e lowermost disk havextending substantially parallel to the bottom of ing a d wnw dly extending peripheral fia s said chamber. said burner having a plate on which the flange 8. In combination, a combustion bowl, a radirests to form a fuel tight joint, and openings at drum secured th t and having an openin the lowermost disk which permit inter-coming, an air intake chamber secured by hinges to said drum and extending through said opening underside of the lowermost disk and the interinto the interior of the drum, said drum being disk p Said fuel P pe Communicating th the adapted to be swung on said hinges through said space between the lowermost disk and said plate,

opening to a position exterior of said drum, a said disks being positioned so close together at liquid fuel burner including a plurality of disks the P p ry as to cause a fuel p s through positioned at the bottom of the bowl, said disks said ipe, up through said ope in s into the inbelng spaced apart to form a passageway for fuel lief-disk Space to leave e P phery of the disks which emerges from the edges of the disks in in s t Suitable for Combustion. thin sheet form, a draft pipe secured to said 13- A iq id fuel burner comprising a P Of chamber and in communication therewith, said concentrically arranged fuel pipes, a pair of draft pipe extending downwardly into said bowl spaced arcuate disks extending transversely of and carrying one of said disks whereby the intake said pipes, the lowermost disk having a downchamber draft pipe and the disk carried thereby Wardly extending peripheral flange, said burner may be swung as a unit on said hinges to a posihaving a plate on which the flange rests to form tion exterior of said drum for inspection. a fuel tight joint, openings in the lower disk 9. In a liquid fuel burner, a combustion unit which permit inter-communication between the comprising a plurality of concentrically mounted space formed at the underside of the lowermost pipes carrying liquid fuel of different grades, a disk and the inter-disk space, he outer one of plate secured to the outer pipe and extending said pipes communicating with the space between transversely thereof, a pair of disks secured to the lowermost disk and the Plate, and the inner the inner pipe and extending transversely therepipe communicating with the space between the of, said plate and disks being spaced fromone two disks. another, the space between the disks being in s 7 HOWARD W. MILLER. communication with the inner pipe and the space munication between the spaced formed at the 

